Electrode material for lithium-ion secondary battery and method for manufacturing the same, electrode for lithium-ion secondary battery, and lithium-ion secondary battery

Abstract

An electrode material includes an inorganic particle and a carbonaceous film coating a surface of the inorganic particle, in which an amount of carbon is 0.8 to 2.5% by mass, and volume of micropores in a micropore diameter range of 2 to 200 nm is 3×10 −2 to 3×10 −1 cm 3 /g. A method for manufacturing an electrode material includes a step of immersing the inorganic particle in an aqueous solution, a step of producing a slurry including the inorganic particle immersed in an aqueous solution, a carbonaceous film precursor, and water, a step of producing a dried substance of the slurry, and a step of calcinating the dried substance in a non-oxidative atmosphere, in which an amount of the carbonaceous film precursor blended into the inorganic particle is 1.0 to 5.0 parts by mass. A lithium-ion secondary battery includes a cathode that is the electrode; an anode; and a non-aqueous electrolyte.

What is claimed is: 
     
       1. An electrode material for a lithium-ion secondary battery comprising:
 an inorganic particle represented by General Formula LiFe x Mn 1-x-y M y PO 4  (0.02≤x≤1.0, 0≤y·0.14, here, M represents at least one element selected from Mg, Ca, Co, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, and rare earth elements); and 
 a carbonaceous film that coats a surface of the inorganic particle, 
 wherein an amount of carbon is 0.8% by mass or more and 2.5% by mass or less, and 
 the carbonaceous film having a volume of micropores in a micropore diameter range of 2 nm or more and 200 nm or less is 3×10 −2  cm 3 /g or more and 3×10 −1  cm 3 /g or less. 
 
     
     
       2. The electrode material for a lithium-ion secondary battery according to  claim 1 ,
 wherein a powder resistance is 1,000 Ω·cm or less. 
 
     
     
       3. The electrode material for a lithium-ion secondary battery according to  claim 2 ,
 wherein a value of D3/D1 measured by means of Raman spectrometry is 0.58 or more and 0.67 or less; 
 wherein D3 is the height between crests of G band and D band peaks appearing near 550 to 680 cm −l  in a visible light laser at a wavelength of 532 nm, and D1 is the height of a D band peak appearing near 1,200 to 1,400 cm −1  in the visible light laser at a wavelength of 532 nm. 
 
     
     
       4. An electrode for a lithium-ion secondary battery comprising:
 the electrode material for a lithium-ion secondary battery according to  claim 1 . 
 
     
     
       5. A lithium-ion secondary battery comprising:
 a cathode; 
 an anode; and 
 a non-aqueous electrolyte, 
 wherein the cathode is the electrode for a lithium-ion secondary battery according to  claim 4 . 
 
     
     
       6. A method for manufacturing the electrode material for a lithium-ion secondary battery according to  claim 1 , the method comprising:
 a step of immersing an inorganic particle represented by General Formula LiFe x Mn 1-x-y M y PO 4  (0.05≤x≤1.0, 0≤y≤0.14, here, M represents at least one element selected from Mg, Ca, Co, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, and rare earth elements) in an aqueous solution having a pH of 7.3 or more and 10.0 or less; 
 a step of producing a slurry including the inorganic particle immersed in the aqueous solution, a carbonaceous film precursor, and water; 
 a step of producing a dried substance of the slurry by drying the slurry; and 
 a step of calcinating the dried substance in a non-oxidative atmosphere of 500° C. or higher and 1,000° C. or lower, 
 wherein an amount of the carbonaceous film precursor blended into 100 parts by mass of the inorganic particle in terms of a carbon element is 1.0 part by mass or more and 5.0 parts by mass or less.